Ensuring a consistent cross-platform experience is an issue that is of increasing importance to developers of various types including, but not limited to, developers of software applications and web developers. For example, a resource such as a web page rendered from one or more underlying source file(s), such as HTML, may appear quite different when rendered by different browsers or other applications. The resource may appear different in different versions of the same browsers. As another example, a web page or cross-platform computer application may appear or behave differently for different operating systems or even when executed by the same operating system but using different screen sizes or other display characteristics.